Storable seating unit

ABSTRACT

A facility including at least one viewing tier having a horizontal supporting surface and a rear wall. An opening is formed in the rear wall of the one tier, and a storable seating unit is movable between a stored position and a deployed position through the opening. The seating unit is supported by the horizontal surface of the one tier, and is configurable in a storable configuration and a deployed configuration. The seating unit height is greater when in the deployed position than in the storable configuration. The opening height is less than the height of the storable seating in the deployed configuration, and greater than the height of the storable seating in the storable configuration.

CROSS REFERENCES TO RELATED APPLICATIONS

[0001] Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] Not Applicable

BACKGROUND OF THE INVENTION

[0003] The present invention relates to storable seating units, in particular to a multilevel storable seating unit which is easily converted from a deployed seating position to provide a clear platform.

[0004] Facilities, such as a stadium, theaters, arenas, and the like, are used for viewing events, such as sporting events, movies, concerts, plays, and the like. Many facilities have a plurality of tiers having supporting surfaces for supporting viewers at different levels to provide the viewers an unobstructed view of the event. Seats are often supported by the supporting surfaces to provide seating for the viewers. These seats are typically fixed to the supporting surface, and removal of the seats is difficult and expensive.

[0005] On occasion, a supporting surface clear of seats is desired. For example, public facilities are required to provide accommodations for individuals with disabilities in accordance with the Americans with Disabilities Act of 1990 (ADA). These accommodations often require providing a clear supporting surface, such as a platform, which can accommodate wheelchairs. When a clear platform is not required, the supporting surface cannot normally be easily converted to conventional seating. Therefore, a need exists for a facility which can accommodate a storable seating unit to provide a clear platform, and for a seating unit which can be easily stored.

SUMMARY OF THE INVENTION

[0006] The present invention provides a facility for viewing an event. The facility includes at least one viewing tier having a horizontal supporting surface and a rear wall. An opening is formed in the rear wall of the one tier, and a storable seating unit is movable between a stored position and a deployed position through the opening. The seating unit is supported by the horizontal surface of the one tier, and is configurable in a storable configuration and a deployed configuration. The seating unit height is greater when in the deployed position than in the storable configuration. The opening height is less than the height of the storable seating in the deployed configuration, and greater than the height of the storable seating in the storable configuration.

[0007] In one aspect of the invention, the storable seating unit includes a support frame movable between a stored position and a deployed position, and having a front surface. A support member is fixed to the frame and spaced rearwardly from the support frame front surface. At least one first seat is fixed to the support frame and provides seating forwardly of the support frame front surface. At least one second seat having an upwardly extending seat back is fixed to the support member. The seat back is movable between a storable configuration and a deployed configuration, wherein in the storable configuration, the seat is moved to reduce the height of the storable seating unit when moving the frame from the deployed position to the stored position.

[0008] A general objective of the present invention is to provide a facility having a storable seating unit to provide a clear space. This objective is accomplished by providing a tiered facility having tiers defined by a supporting surface and a rear wall in which seating can be slipped through an opening in the rear wall to clear the supporting surface.

[0009] Another objective of the present invention is to provide a storable seating unit which can be slipped through an opening of a rear wall of a tier. This objective is accomplished by providing a seating unit having seats with movable seat backs which can be moved to reduce the seating unit height below the height of the opening, such as by pivoting the seat back relative to the stanchion or pivoting the stanchion to move the seat back to a lower position.

[0010] This and still other objects and advantages of the present invention will be apparent from the description which follows. In the detailed description below, preferred embodiments of the invention will be described in reference to the accompanying drawings. These embodiments do not represent the full scope of the invention. Rather the invention may be employed in other embodiments. Reference should therefore be made to the claims herein for interpreting the breadth of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a cross sectional view of a tiered facility incorporating the present invention with a storable seating unit in a deployed position;

[0012]FIG. 2 is a cross sectional view of the tiered facility of FIG. 1 with the storable seating unit in a stored position;

[0013]FIG. 3 is a detailed view of the seating unit of FIG. 1 in a deployed configuration;

[0014]FIG. 4 is a detailed view of the seating unit of FIG. 1 in a storable configuration;

[0015]FIG. 5 is a front view of the seating unit of FIG. 1;

[0016]FIG. 6 is a plan view of the bottom of the carriage of the seating unit of FIG. 1;

[0017]FIG. 7 is a front view of the carriage of FIG. 1 with the seats not shown for clarity;

[0018]FIG. 8 is an elevation view of a side of the carriage of FIG. 1; and

[0019]FIG. 9 is a plan view of the top of the carriage of FIG. 1 with an extension attached.

DETAILED DESCRIPTION OF THE INVENTION

[0020] As shown in FIGS. 1 and 2, a facility 10, such as a stadium used for viewing an event, such as a basketball game, has a plurality of tiers 12. Each tier 12 includes a rear wall 14 and a horizontal supporting surface 16 which supports viewers of the event. At least one of the tiers 12 supports a storable seating unit 20 which can be deployed to a deployed position to provide seating for the viewers, or stored away to a stored position to provide a clear deck 22. The seating unit 20 is stored in a storage space 24 accessed through an opening 26 formed in the tier rear wall 14 behind the deployed seating unit 20 to clear the deck 22, such as for individuals requiring special accommodations, such as required by the ADA. Preferably, a guard rail 28 is mounted adjacent an edge of the deck 22 or platform extension 172 when the seating unit 20 is in the stored position.

[0021] Referring to FIGS. 3-8, the storable seating unit 20 includes a carriage 30 which is movable between a stored position (shown in FIG. 2) and a deployed position (shown in FIG. 1). A lower level of seats 32 is mounted to the carriage 30, and an upper higher level of seats 34 is mounted to the carriage 30 rearwardly of the lower level of seats 32. A platform 36 mounted to the carriage 30 between the upper and lower levels of seats 34, 32 provides a floor for users of the upper level of seats 34. Advantageously, the upper level of seats 34 and the platform 36 can be pivoted to reduce the height of the seating unit 20 for storage in the storage space 24 having an opening 26 which is less than required for seating having a fixed height to minimize storage space requirements.

[0022] Looking particularly at FIG. 6, the carriage 30 has a welded rectangular base 38 including a front horizontal member 40 and rear horizontal member 42 joined by a pair of opposing side members 44. An intermediate horizontal member 46 extends between the side members 44, and is positioned between the front and rear members 40, 42. Rear intermediate structural members 48 having one end fixed to the intermediate horizontal member 46 and an opposing end fixed to the rear horizontal member 42 stiffens the base 38 and provides support for a back storage deck plate 98. Additional structural members 50 can be provided, such as perpendicular or diagonal members between any of the horizontal members 40, 42, 44, 46 and/or an intermediate structural member 48 as required to provide a stiff structure, without departing from the scope of the present invention.

[0023] As shown in FIG. 3, an upper level seat support 50 supports the upper level of seats 34, and includes vertical and horizontal members 52, 54, 56. Vertical upper level seat supports 52 extend vertically from the intermediate horizontal member 46, and are fixed thereto using methods known in the art, such as welding, bolting, and the like. A first horizontal cross member 54 is fixed to a forward facing surface of each of the upper level seat supports 52 proximal the top of each support 52 to increase the rigidity of the upper level seat support 50. A second horizontal cross member 56 is fixed to the top of each upper level seat support vertical member 52 to close off the open top of each member 52 if tube steel is used.

[0024] Referring particularly to FIGS. 7 and 8, a side frame 58 is fixed to each side member 44 using methods known in the art, such as welding. Each side frame 58 includes a first vertical member 60 extending vertically from the side member 44 aligned with the upper level seat support vertical member 52 and a second vertical member 62 aligned with a platform support 64. A horizontal member 66 joins the side frame vertical members 60, 62, to stiffen the frame 58. A pair of plates 68 extend forwardly from the second vertical member 62 for locking the platform support 64 beneath the platform 36.

[0025] An intermediate frame 70 having a vertical member 72 aligned with the platform support 64 can be provided for carriages supporting more than one seat in a level. A plate 74 extends forwardly from the intermediate frame vertical member 72 for locking the platform support 64 beneath the platform 36.

[0026] The platform support 64 supports the platform in the deployed configuration, and includes vertical platform supports 76 joined by a horizontal platform support 78. The vertical platform supports 76 extend upwardly from the front horizontal member 40, and are pivotally connected thereto using methods known in the art, such as a hinge 80. The horizontal platform support 78 joins the vertical platform supports 76 together, such that the vertical platform supports 76 pivot together. Preferably, gas charged struts (not shown) having one end pivotally fixed to the platform and an opposing end pivotally fixed to the carriage prevent the platform from dropping freely when disengaged from the support 78.

[0027] A lock plate 82 locks the platform 36 in the deployed configuration, and is disengaged when the platform is in the storable configuration. As shown in FIGS. 3 and 4, the lock plate 82 having a hole formed therein extends outwardly from each end of the horizontal platform support 78 for engagement with the plates 68, 74 extending from the side frame 58 or an intermediate frame 70. In the deployed configuration shown in FIG. 3, each lock plate hole is aligned with the holes in the pair of plates 68 fixed to the adjacent carriage side frame 58 or the hole in the plate 74 fixed to the intermediate member 70.

[0028] A pin 83 is inserted through the aligned holes to prevent pivotal movement of the platform support 64 and disengagement of the horizontal platform support 78 from the platform 36. Preferably, the pin 83 is secured in the aligned holes, such as by a padlock, to prevent inadvertent or unauthorized removal of the pin 83. In the storable configuration shown in FIG. 4, the pins 83 are disengaged from the lock plates 82 to release the platform 36, and the platform support 78 is pivoted forwardly to disengage the platform 36 from the support 78.

[0029] An intermediate wheel mounting plate 86 is fixed adjacent an inner surface 88 of each side member, and is stiffened by a top wall 90 supported by opposing vertical walls 92. The top wall 90 has one end fixed to an end upper level seat support 52, and extends forwardly toward the front horizontal member 40. A portion of the top wall extends downwardly toward the supporting surface 16. The side vertical walls 92 are joined to each edge of the top wall 90. Preferably, when the platform is pivoted downwardly, it is supported by a forward edge of the plate 86.

[0030] Looking particularly at FIG. 6, a wheel mounting plate 96 is fixed to the top of each outermost intermediate horizontal member 48 and adjacent frame side member 44, and extends across the gap defined between the two members 44, 48. A top plate 98, such as a checkered plate, covers the spaced defined between the intermediate horizontal member 46 and rear horizontal member 42 between the rear intermediate supports 48, and is fixed to the members 42, 46, 48 using methods known in the art, such as screws, welding, and the like. Preferably, the portion of the carriage including the top plate extends into the storage space when the seating unit is deployed to provide storage for items not in use, such as signs, folding chairs, maintenance tools, guard rails, and the like.

[0031] Support wheels 100, 102, 104 rotatably mounted to the carriage 30 engage the support surface 16, such as a stadium floor, to reduce friction when moving the seating unit 20 between the stored position and the deployed position. Front support wheels 100 are rotatably mounted in each side member 44 proximal to the front horizontal member 40 to prevent the carriage from tipping when the seating unit 20 is loaded unevenly, such as when only the lower level of seats 32 are occupied. Intermediate and rear support wheels 102, 104 are mounted adjacent an inwardly facing surface of each frame side member 44. Preferably, the intermediate support wheels 102 are rigid casters mounted to the front end of the intermediate wheel mounting plate 86, and the rear support wheels 104 are rigid casters mounted to the rear wheel mounting plates 96. Additional support wheels can be provided, such as fixed to one of the intermediate structural members, without departing from the scope of the present invention.

[0032] As shown in FIG. 4, a drop bolt 106 slidably inserted through a vertical hole 108 formed in each side frame member 44 engages a bore 110 formed in the supporting surface 16 to lock the seating unit 20 in the deployed position. The engaged drop bolt 106 prevents unintended movement of the carriage 30, and can be easily disengaged from the bore 110 when movement of the carriage 30 is desired. Of course, other methods known in the art can be used to lock the seating unit 20 in a position, such as horizontal pins engaging a bracket, a jack which lifts the support wheels away from the supporting surface, and the like, without departing from the scope of the present invention.

[0033] Referring to FIGS. 3 and 4, the lower level of seats 32 is mounted to a front face 112 of the carriage front horizontal member 40 with mounting plates 114, and includes one or more individual seats 116. Each lower level seat 116 includes a pair of opposing stanchions 118 which support a seat back 120 and a pivotally mounted body support 122. The body support 122 extends forwardly of the front face 112 of the carriage 30 to provide seating forwardly of the carriage front horizontal member 40.

[0034] As shown in FIG. 5, adjacent seats 116 can share an adjacent stanchion 118, such that two seats 116 have a total of three stanchions 118. The seat stanchions 118 are fixed to the front horizontal member 40 using methods known in the art, such as bolts, and the like. Preferably the mounting plates 114 having bolts holes formed therethrough are welded to the horizontal member front face 112, and bolts 124 extend through the bolt holes to mount the seat stanchions 118 to the frame horizontal member 40.

[0035] The upper level of seats 34 is pivotally mounted to the first horizontal cross member 54 at a higher level than the lower level of seats 32, and includes one or more individual seats 126. In a deployed configuration, the higher seat level provides the occupants of each seat 126 in the upper level 34 with an unobstructed view of the event. Each upper level seat 126 includes a pair of opposing stanchions 128 which support a seat back 130 and a pivotally mounted body support 132. As in the lower seats 116, adjacent upper level seats 126 can share an adjacent stanchion 128, such that two seats 118 have a total of three stanchions 128.

[0036] The upper level seats 126 are pivotally mounted for forwardly pivotal movement into a storable configuration to reduce the overall height of the seating unit 20 for storage. Although the seats 126 disclosed herein have pivotally mounted stanchions, the seats can have non-pivoting stanchions and seat backs 130 which pivot rearwardly or forwardly to reduce the overall height of the seating unit 20 without departing from the scope of the present invention.

[0037] The seat stanchions 128 are fixed to a mounting plate 134 using methods known in the art, such as bolts, and the like. Preferably, the mounting plate 134 extends along the length of the horizontal cross member 54, and a row of upper level seats 126 are fixed thereto. The mounting plate 134 is hingedly connected, such as with a hinge 135, to the first horizontal cross member 54 to pivotally mount a row of upper level seats 126 to the first horizontal cross member 54.

[0038] A locking mechanism 136 fixed to the mounting plate 134 behind each upper level seat 126 engages a lock plate 138 fixed to the first horizontal cross member 54. The locking mechanism 136 includes a pair of opposing sandwich plates 140 between which is received the lock plate 138 when the seat upper level 34 is in the deployed configuration. A hole 142 formed in one sandwich plate 140 is aligned with a hole 142 formed in the other sandwich plate 140. The lock plate 138 includes a hole 144 formed there through which aligns with the sandwich plate holes 142 for receiving the pin 84 therethrough to secure the row of upper level seats 34 in the deployed configuration.

[0039] The platform extends 36 between the upper and lower level of seats 34, 32 below the upper level of seats 34 to provide a floor for users of the upper level of seats 34. The platform 36 has one edge 146 pivotally connected to the first horizontal cross member 54, such as by a hinge 148. In the deployed configuration, an opposing platform edge 150 is supported by the platform support 64. Preferably, an angle 152 (best shown in FIG. 4) fixed to the horizontal platform support 78 has one leg 154 extending rearwardly from a rearwardly facing surface 156 of the horizontal platform support 78 to provide additional support to the platform 36.

[0040] In the storable configuration, the seating unit 20 is slidably moved rearwardly to the stored position in the storage space 24 formed behind the deployed seating unit 20. Preferably, the storage space 24 is disposed behind the deployed seating unit 20, and beneath a structure supporting fixed conventional seating 166 above and behind the deployed seating unit 20. The storage space 24 includes a top wall 168 supporting the fixed seating 166, a rear wall 168, and a stored seating unit support 170. The stored seating unit support 170 can be any conventional support structure, such as a conventional concrete floor, rails aligned with the support wheels, and the like.

[0041] The opening 26 in the rear wall 14 provides access to the storage space 24 from the tier horizontal surface 16. Preferably, the height of the opening (i.e. the distance between the inner surface 173 of the top wall and the support surface 16) into the storage space 24 is sufficient to provide minimal clearance between the seating unit 20 in the storable configuration for unobstructed movement between the deployed position and the stored position. Most preferably, the height of the opening is less than the height of the same number of levels of conventional seating to minimize the height between seating tiers 12.

[0042] Rollers (not shown) mounted to each opening side wall engage the carriage sides to guide the seating unit 20 between the stored position and the deployed position. Although not required to practice the invention, the rollers prevent the seating unit 20 from skewing when moving between the positions. Of course, other methods known in the art can be used to prevent skewing, such as guide rails, bumpers, and tracks formed or fixed to the side walls or support structure, and the like.

[0043] Cable lanyards 175 having one end fixed to the carriage 30 and an opposing end fixed to the storage area rear wall 168 or other point fixed relative to the seating unit 20 prevents the seating unit 20 from moving beyond a predetermined point on the supporting surface 16. Of course, any method known in the art, such as stops fixed to the support structure and the like, can be used to prevent unintended movement of the seating unit beyond a predetermined point without departing from the scope of the present invention.

[0044] As shown in FIG. 9, an extension 158 can be mounted to an end of the carriage 30 to provide additional lower level seating. Each extension 158 includes a frame 159 having an extension bottom horizontal member (not shown) for mounting additional seats thereto, a vertical member 161 extending upwardly from the distal end of the front horizontal member, and a top horizontal member 163 which is fixed proximal to the top of the vertical member and extends toward the carriage directly above the bottom horizontal member. Additional vertical members 167 extending between the top and bottom horizontal members can be provided to further stiffen the extension frame.

[0045] The proximal ends of the top and bottom horizontal members 163, are fixed to the carriage using methods known in the art, such as bolting, welding, and the like. Preferably, the extension 158 is positioned, such that the extension front horizontal member 160 is aligned with the frame front horizontal member 40 to provide a continuous row of lower level seats.

[0046] An angled back brace 162 stiffens the extension 158. The back brace 162 has one end 164 fixed to the extension bottom horizontal member 160 distal end and an opposing end 166 fixed to the frame side member 44 spaced rearwardly from the frame front horizontal member 160. The back brace 162 stiffens the extension 158 to prevent unintended pivotal movement of the extension frame 159. One or more lower level seats, such as described above, are mounted to the extension front horizontal member 160, as described above for mounting the seats 116 to the frame front horizontal member 40.

[0047] Steps (not shown) can be fixed to the carriage 30 provide access to the platform 36, and thus the upper level of seats 34. The steps can have any number of risers, as required, to provide access to the platform 36, and are formed using methods known in the art. The steps are fixed to the carriage 30, such that the steps move with the carriage 30. Preferably, however, the steps are detachable or independent of the seating unit 20 to provide easy access to the storage space 24 without completely removing the seating unit from the storage space opening 26.

[0048] The storable seating unit 20 is deployed by sliding the seating unit 20 forwardly out of the storage space 24 onto the supporting surface 16 until the upper level seats 34 are clear of the storage space opening 26 and properly positioned, such that the drop bolt 106 is aligned with the bore 110. The drop bolt 106 is then engaged with the bore 110, and the upper level of seats 34 are pivoted upwardly and locked into the deployed configuration. The platform support 64 is then pivoted forwardly, and the platform 36 is pivoted upwardly. The platform support 64 is then pivoted rearwardly underneath the front edge of the platform 36 to engage the platform locking plates 82 with the side and intermediate frame plates 68, 74. The platform 36 and platform support 64 are locked in position by inserting the pin 83 in the aligned holes of the respective lock plate 82 and plates 68, 74.

[0049] The storable seating unit 20 is stored by unlocking the platform 36 from the platform support 64 and pivoting the platform support 36 forwardly to disengage the lock plates 82 from the side or intermediate frame plates 68, 74. The platform 36 is then pivoted downwardly to provide room for pivoting the upper level of seats 34 forwardly. Pins 84 securing the upper level of seats 34 in the deployed configuration are removed, and the seat upper level 34 is pivoted forwardly to reduce the overall height of the seating unit 20. The seating unit is then slipped rearwardly into the storage space 24 through the opening 26 to provide a clear deck 22.

[0050] While there has been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention defined by the appended claims.

[0051] For example, as shown in FIG. 2, the cleared deck 22 can be extended to provide a larger deck area by pivotally mounting a horizontally fixed row of seats 170 directly forward of the deck to the tier rear wall directly below the deck 22. When a larger deck 22, or more space in front of the deployed seating unit 20, is desired, the horizontally fixed seats 170 are pivoted forwardly and a platform extension 172 is erected over the pivoted horizontally fixed seats 170. The seat stanchions 174 of the fixed pivotal seating 170 are modified to provide a shorter stanchion, and are mounted at a higher elevation than a conventional seat, such as described above, to allow sufficient pivotal movement to avoid interference with the installed platform extension 172. 

We claim:
 1. A storable seating unit comprising: a support frame movable between a stored position and a deployed position, and having a front surface; a support member fixed to said frame and spaced rearwardly from said support frame front surface; at least one first seat fixed to said support frame and providing seating forwardly of said support frame front surface; at least one second seat having an upwardly extending seat back, and being fixed to said support member, said seat back being movable between a storable configuration and a deployed configuration, wherein in said storable configuration, said seat is moved to reduce the height of the storable seating unit when moving said frame from said deployed position to said stored position.
 2. The storable seating unit as in claim 1, in which said seat back is pivotally mounted to stanchions fixed to said support member.
 3. The storable seating unit as in claim 1, in which said seat back is fixed to stanchions pivotally fixed to said support member.
 4. The storable seating unit as in claim 1, in which said second seat is at a higher level than said first seat in said deployed configuration.
 5. The storable seating unit of claim 1, in which a platform extends between said second seat and said first seat.
 6. The storable seating unit of claim 5, in which said platform is pivotally mounted to said frame, wherein said platform is pivoted to provide clearance for pivoting said second seat when moving said frame from said deployed position to said stored position.
 7. The storable seating unit of claim 6, in which a support member fixed to said frame supports said pivoted platform and prevents an edge of said platform from striking a surface supporting said frame.
 8. The storable seating unit as in claim 1, in which said frame includes support surface engaging wheels to reduce friction when moving said frame between said stored position and said deployed position.
 9. The storable seating unit as in claim 1, including a restraint mechanism which prevents said frame from moving beyond said deployed position.
 10. The storable seating unit as in claim 1, including a locking mechanism which locks said frame in a fixed position.
 11. The storable seating unit as in claim 1, including an extension extending said first mounting member for mounting at least one additional seat thereto.
 12. A facility for viewing an event comprising; at least one viewing tier having a horizontal supporting surface and a rear wall; an opening having a height, and being formed in said rear wall of said tier; a storable seating unit having a height and being supported by said supporting surface, said seating unit being movable between a stored position and a deployed position through said opening and being configurable in a storable configuration and a deployed configuration, wherein said seating height is greater when in said deployed configuration than in said storable configuration, and said opening height is less than the height of said storable seating in said deployed configuration, and said opening height is greater than the height of said storable seating in said storable configuration.
 13. The facility of claim 12, in which said seating unit includes a support frame movable between a stored position and a deployed position, and having a front surface; a support member fixed to said frame and spaced rearwardly from said support frame front surface; at least one first seat fixed to said support frame and providing seating forwardly of said support frame front surface; at least one second seat having an upwardly extending seat back, and being fixed to said support member, said seat back being movable between a storable configuration and a deployed configuration, wherein in said storable configuration, said seat is moved to reduce the height of the storable seating unit when moving said frame from said deployed position to said stored position.
 14. The storable seating unit as in claim 13, in which said seat back is pivotally mounted to stanchions fixed to said support member.
 15. The storable seating unit as in claim 13, in which said seat back is fixed to stanchions pivotally fixed to said support member.
 16. The facility as in claim 12, in which said second seat is at a higher level than said first seat in said deployed configuration.
 17. The facility as in claim 12, in which a platform extends between said second seat and said first seat.
 18. The facility as in claim 17, in which said platform is pivotally mounted to said frame, wherein said platform is pivoted to provide clearance for pivoting said second seat when moving said frame from said deployed position to said stored position.
 19. The facility as in claim 18, in which a support member supports said pivoted platform and prevents an edge of said platform from striking the ground.
 20. The facility as in claim 12, in which said frame includes ground engaging wheels to reduce friction when moving said frame between said stored position and said deployed position.
 21. The facility as in claim 12, including a restraint mechanism which prevents said frame from moving beyond said deployed position.
 22. The facility as in claim 12, including a locking mechanism which locks said frame in a fixed position.
 23. The facility as in claim 12, including an extension extending said first mounting member for mounting at least one additional seat thereto.
 24. The facility as in claim 21, in which a rear wall of a second viewing tier abuts a forward edge of said horizontal supporting surface, and a third seat is pivotally mounted to said second viewing tier rear wall wherein pivoting said third seat reduces the height of said third seat below the horizontal supporting surface.
 25. The facility as in claim 21, in which a removable platform abuts a forward edge of said supporting surface to extend said supporting surface over said third seat. 